In general, the seats used in transport vehicles face problems because of the volume of the seat structure, which must be compatible with other structures of the vehicle, space restrictions such as for example access to emergency exits, or the installation of equipment which may be mounted temporarily, while providing a desired comfort level for the seat occupant.
Often the seat comprises adjustment elements accessible to the seat occupant, which allow the latter to adapt the ergonomics of the seat to his/her anatomy or to particular conditions. Thus often a seat is adjustable with a certain amplitude in the longitudinal position, in the height of the seat base, the recline of the backrest etc.
For example, the seat described in patent application EP 2305561 comprises a rigid bucket, the height of which is adjustable on subframe uprights which are inclined towards the rear. As a result of this arrangement, the rearmost part of the seat moves back when the bucket is raised and consequently risks interfering with a structure situated behind the seat.
In general, the movable parts of the seat must avoid interference with other vehicle structures, which leads to additional constraints which may limit the adjustment potential and lead to the implementation of complex and heavy solutions, which are in themselves sources of a loss of reliability of the seat and an increase in its production and maintenance costs.
For these various reasons, a seat adapted to the environment of a location in a given vehicle is not necessarily adapted to the environment of another vehicle, or another location in the same vehicle.
In these situations, it is then necessary either to have a different seat to suit specific situations, or to degrade the adjustment potential of the seat. For example, in passenger transport aircraft it is known to eliminate the possibility of reclining the backrest or to block this when the seat is installed in the cabin with the seat back very close to a partition.